Hi,
We are using the BG95-M3 in a product and currently have an issue with the GNSS location being cached. We are trying to clear the data with AT+QGPSDEL=0 before enabling GNSS with AT+QGPS=1. When moving between places it seems it always use the previous location instead of the current one so the current location is cached once.Have anyone observed something similar? A wrong setting or?
Any feedback is more than welcome and highly appreciated.
Kind Regards,
Jeppe
Hi Jeppefrandsen,
Please confirm your BG95-M3 software version by sending ATI command.
After sending AT+QGPSDEL=0 and AT+QGPS=1, the module should have enforce cold start. And assistant data, time and position data are cleared.
May I ask how far between the 2 places? What are the positions output from BG95 at 2 difference place(static test)?
Best regards.
Hi Raphael,
Thank you very much for the reply!
The software version used is 01.012.01.012
What we are seeing (after more tests) is that the AT+QGPSDEL=0 command is not always clearing the data but works in most cases. When we test we stay at the same location just to see that it would do a cold start. Here we sometimes see that the location is retrieved within a second or few seconds which I guess means it is still cached somewhere?
Kind Regards,
Jeppe
Hi Jeppefrandsen,
From your description, BG95 have probability to appear a significant drift from previous location to curruent position. Can you provide some records for this problem.
If the module enforce a cold start. The previous loaction data should be cleared up. May I ask how many devices from your side reappear this problem? What is the probability of this problem?
Best regards.
Hi @Raphael-Q
We have seen this issue on almost all devices but first lately found out that it seems to be cached. We will try to provide a record. We changed to do the AT+QGPSDEL=0 after disable of GNSS as it seemed a bit better (more likely to to a cold start at next GNSS enable). We also added an additional workaround to do a power off/on of the modem if the GNSS location is fetched within 10 seconds (must be a cached location then). This for now seems to improve the problem but would be nice to find out what causes AT+QGPSDEL=0 to not always delete the data. Are there some conditions in the firmware where AT+QGPSDEL=0 will not do anything? Could it be some timing issue?
Kind Regards,
Jeppe
Hi Jeppefrandsen,
Generally, GNSS location data is stored in RAM. After a completely power off or cold start, the data should have been cleared.
Best regards.
Hi @Raphael-Q,
Should it be enough by using the PWRKEY for turning off and on the module or is e.g., RESET or removing the supply voltages needed?
Kind Regards,
Jeppe
Hi Jeppefrandsen,
PWRKEY is okay. Can module restore from abnormal state?
Best regards.
Hi @Raphael-Q,
No, not all the time. But we are right now using a workaround to power off and on via the PWRKEY if the location seems cached (takes less than 10 seconds to get a location). This seems for now to work.
This is why I was not sure if the memory was reset when using PWRKEY or if reset or removing the power supply completely would be needed.
Kind Regards,
Jeppe
Hi Jeppefrandsen,
I will send you the latest firmware for BG95-M3 by message. Please upgrade and compare with the older one.
Best regards.
Hi @Raphael-Q,
Thanks a lot! It however seem to be the same after updating. Are you sure that the location data is stored in RAM and not NVRAM? Is there e.g. an AT command to clear the RAM, reset the device or some other way of removing the location data?
Kind Regards,
Jeppe